It looks like you have a broken C++ compiler installation. The code that is failing to compile is a system-level C++ header file, not an Open MPI file.

The only part of Open MPI that is C++ is the optional VampirTrace package; you can disable building it and the rest of Open MPI will work fine. Use "./configure --enable-contrib-no-build=vt ..." when configuring Open MPI and that will disable building VT.